Delta Air Lines Inc. (NYSE: DAL)

Delta Air Lines is one of the world's largest and most profitable airlines, operating a hub-and-spoke network centered on Atlanta, the busiest airport on Earth. The airline has differentiated itself through premium service, operational reliability, and a loyalty program (SkyMiles) that generates billions in revenue through its partnership with American Express. Delta also holds stakes in airlines including LATAM, Korean Air, and Virgin Atlantic.

Delta earns revenue from passenger ticket sales, cargo, and a highly lucrative co-branded credit card partnership with American Express that generates over $7 billion annually. The premium cabin strategy—investing in lie-flat seats, Delta One Suites, and Sky Clubs—drives higher yields per passenger.

Delta was founded in 1924 as a crop-dusting operation in Macon, Georgia. The airline filed for bankruptcy in 2005 and emerged in 2007 as a leaner operation. The merger with Northwest Airlines in 2008 created the world's largest airline at the time. Under CEO Ed Bastian, Delta has consistently led the US airline industry in profitability and customer satisfaction.